ABSTRACT

The present study highlights the effect of different nitrogen sources and their concentration, inoculum size and size of vessel on bioactivity of rhizosphere soil fungi Aspergillus ibericus from Ficus religiosa against opportunistic pathogens, through the production of secondary metabolite exhibiting antimicrobial activity. The various organic (peptone) and inorganic (ammonium nitrate, ammonium chloride and sodium nitrate) nitrogen sources were used in the fermentation medium. The optimization of inoculum size for production of antimicrobial metabolite was carried out by using fungal disks of various sizes viz. 10mm, 12mm, 14mm, 16mm and 18mm cut from four days old colony of A. ibericus added as inoculum in each flask. Antimicrobial metabolite obtained from A. ibericus was found to be effective against test microbes when dextrose was used as a carbon source. The optimization of size of fermentation vessel on antimicrobial metabolite production was carried out by taking Erlenmeyer’s flasks of different sizes viz. 100, 250, 500 and 1000ml, respectively. The fungus exhibited maximum antimicrobial activity in the presence of unmodified potato dextrose broth without any nitrogen source. Fungal disk size of 10mm was found to be optimum for maximum yield of antimicrobial metabolite. Whereas, 250ml vessel size was found to be the optimized size for fermentation on small scale in laboratory for production of fungal bioactive metabolite by strain A. ibericus. Keywords: Rhizosphere Soil, Oppurtunistic Pathogens, Aspergillus ibericus, Nitrogen sources, inoculum size, fermentation vessel size
Publication date: 01/03/2020

https://ijbpas.com/pdf/2020/March/MS_IJBPAS_2020_4986.pdf

Download PDF
https://doi.org/10.31032/IJBPAS/2020/9.3.4986